Untitled

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Q2</title>
</head>
<body>
<input type="text" id="distance" style="width: 50%" placeholder="Distance from this station to source, start with 0, split by space"/><br/>
<input type="text" id="cost" style="width: 50%" placeholder="Cost of each station, start with 0, split by space"/><br/>
<input type="text" id="travel" style="width: 50%" placeholder="Maximum travel distance" /><br/>
<button onclick="solve()">Solve</button>
<div id="result"></div>

<script>
    var best;
    function solve()
    {
        var input = getInput();
        var result = calculate(input);
        showResult(input, result);
    }

    function getInput ()
    {
        var distanceText = document.querySelector("#distance").value;
        var costText = document.querySelector("#cost").value;
        var travelDistance = Number(document.querySelector("#travel").value);
        var distanceArr = distanceText.split(" ").map(function(text){return Number(text);});
        var costArr = costText.split(" ").map(function(text){return Number(text);});
        return {
            distance: distanceArr,
            cost: costArr,
            travelDistance: travelDistance
        };
    }

    function calculate(input)
    {
        best = [];
        var x = input.distance;
        var cost = input.cost;
        var capacity = input.travelDistance;

        best.push(0);
        for (var i = 0; i < x.length - 1; i++)
        {
            best.push(-1);
        }

        var answer = findBest(x, cost, capacity, x.length - 1);
        return answer;
    }

    // Implementation of BestCost function
    var findBest = function(distances, costs, capacity, distanceIndex)
    {
        if (best[distanceIndex] != -1)
        {
            return best[distanceIndex];
        }
        var minDistanceIndex = findMinDistance(capacity, distances, distanceIndex);
        var answer = findBest(distances, costs, capacity, minDistanceIndex) +
            calculateCost(distances, costs, capacity, minDistanceIndex, distanceIndex);
        for (var i = minDistanceIndex + 1; i < distanceIndex; i++)
        {
            var newAnswer = findBest(distances, costs, capacity, i) +
            calculateCost(distances, costs, capacity, i, distanceIndex);
            if (newAnswer < answer)
            {
                answer = newAnswer;
            }
        }
        best[distanceIndex] = answer;
        return answer;
    }

    // Implementation of MinGasStation function
    function findMinDistance(capacity, distances, distanceIndex)
    {
        for (var i = 0; i < distances.length; i++)
        {
            if (distances[distanceIndex] - distances[i] <= capacity)
            {
                return i;
            }
        }
    }

    // Implementation of Cost function
    function calculateCost(distances, costs, capacity, a, b)
    {
        var distance = distances[b] - distances[a];
        return costs[b] * (distance / capacity);
    }

    function showResult(input, result)
    {
        var resultText = "Total cost is "+ result;
        document.querySelector("#result").innerHTML = resultText;
    }
</script>
</body>
</html>